Foreign Secretary William Hague has been asked to clarify whether a British man who died in China and is now at the centre of a murder investigation ever worked as a spy.
Hague came under pressure from to explain why Britain did not intervene sooner over the murder of businessman Neil Heywood.
The Foreign Affairs Select Committee wrote to Hague asking why ministers were not immediately informed about rumours that surfaced in January that there were suspicious circumstances surrounding his death.
In a letter from committee chairman Richard Ottaway, it also raised speculation about Heywood's "profession", and whether he had supplied information to the British Consulate or Embassy.
The Tory MP asked the Foreign Secretary to clarify Heywood's relationship with the British Consulate-General in Chongqing and the British Embassy in Beijing.
"For instance, did he supply the British Consulate or Embassy with information, either on a formal or informal basis?" he asked.
According to the Telegraph officials have denied Heywood was employed by the government, with former spy chiefs quoted as describing him as a "comical" figure who was not suited to espionage.
State media reports in China have suggested that investigations by authorities there indicate Heywood, 41, was a victim of homicide.
He was a friend of the family of Bo Xilai, a former rising star in Chinese politics who served as local party chief in Chongqing but was suspended from the Politburo in April amid allegations of "serious discipline violations".
Heywood died in the city of Chongqing last November, and Chinese authorities initially said it was down to alcohol overconsumption.
Hague said this week that Foreign Office staff were aware on 18 January of rumours that there may have been suspicious circumstances.
But it was not until after a former Chongqing vice-mayor and chief of police Wang Lijun raised the concerns with the US consulate on February 6 that officials informed Hague.
The UK subsequently asked China to investigate, which it has now promised to do.
Unconfirmed media reports suggest that police suspect Heywood may have been poisoned after threatening to expose a plan by Bo's wife Gu Kailai to move money abroad.
In his letter, Ottaway wrote: "From your statement, it appears that ministers were informed of Neil Heywood's case only after allegations were made by Wang Lijun on February 6.
"Why were earlier rumours about Mr Heywood's death, which reached FCO staff in January, not communicated to ministers immediately?"
Check out the news of the day in pictures below:
Employees pose putting the finishing touches to new waxwork statues of Britain's Prince William (R) and Catherine, Duchess of Cambridge (L) as they are unveiled at Madame Tussauds in Blackpool, north-west England on April 19, 2012. The Duchess is dressed in an exact copy of the stunning Jenny Packham dress she wore for the ARK charity dinner, the first time she and Prince William appeared as a married couple. (Photo credit: ANDREW YATES/AFP/Getty Images)
Ekaterina Samutsevich, a member of female Russian punk band Pussy Riot waves as she is escorted to the court in Moscow, on April 19, 2012. Three members of the all-woman punk band 'Pussy Riot' were detained two months ago, after they climbed on the altar of Moscow's Christ the Saviour Cathedral - the country's central place of worship - and sang a song they called a 'Punk Prayer'. The women have been charged with hooliganism committed by an organised group - an unusually harsh charge for protesters. (Photo credit: ALEXANDER NEMENOV/AFP/Getty Images)
Police officers detain a supporter of female Russian punk band Pussy Riot outside the court in Moscow, on April 19, 2012, before the hearings on the Pussy Riot case. Three members of the all-woman punk band 'Pussy Riot' were detained two months ago, after they climbed on the altar of Moscow's Christ the Saviour Cathedral -- the country's central place of worship -- and sang a song they called a 'Punk Prayer'. The women have been charged with hooliganism committed by an organised group -- an unusually harsh charge for protesters. (Photo credit: ANDREY SMIRNOV/AFP/Getty Images)
Andy Murray of Britain plays a return shot to Julien Benneteau of France during their match at the Monte Carlo Tennis Masters tournament in Monaco, Thursday, April 19, 2012. (Photo credit: AP Photo/Lionel Cironneau)
France's Julien Benneteau reacts as he lays on the ground after a fall during his match againt's British Andy Murray during the Monte-Carlo ATP Masters Series Tournament tennis match, on April 19, 2012 in Monaco. Murray won the match after Benneteau injured both his right ankle and arm. (Photo credit: VALERY HACHE/AFP/Getty Images)
Two Iraqi women walk along a street in the capital Baghdad as a sand storm envelops the city on April 19, 2012. (Photo credit: SABAH ARAR/AFP/Getty Images)
Israelis pause during a two-minute siren in memory of victims of the Holocaust in the market in Jerusalem, Thursday, April 19, 2012. The day is one of the most solemn on Israel's calendar. Restaurants and places of entertainment shut down, and radio and TV programming focuses on Holocaust documentaries and interviews with survivors. (Photo credit: AP Photo/Bernat Armangue)
France's incumbent President and UMP ruling party's candidate for the 2012 presidential election, Nicolas Sarkozy speaks during a campaing meeting on April 19, 2012 in the French city of Saint-Maurice outside Paris. (Photo credit: MICHEL EULER/AFP/Getty Images)
Newly-recruited Thai women rangers take part in a training session at a military camp in Narathiwat province on April 19, 2012. More than 5,100 people have been killed - both Muslims and Buddhists - in attacks across Pattani, Yala and Narathiwat since unrest escalated in January 2004, according to Deep South Watch which monitors the violence. (Photo credit: MADAREE TOHLALA/AFP/Getty Images)
Philippine marines carry a colleague acting as fallen enemy during an ambush simulation as part of the two-week PH-US military exercise inside the Philippine marines training center in Ternate town, Cavite province, south of Manila on April 19, 2012. The Philippines hailed the start of major war games with the United States on April 16, as a timely boost to the two nations' military alliance amid growing regional security challenges. (Photo credit: TED ALJIBE/AFP/Getty Images)
One Direction fans wait at Auckland International Airport for the arrival of the band on April 19, 2012 in Auckland, New Zealand. One Direction peforms to sold-out audiences in Auckland on Saturday and Wellington on Sunday. (Photo credit: Phil Walter/Getty Images)
Indonesian militant Umar Patek arrive in handcuffs and escorted by armed police commandos at the Jakarta court on April 19, 2012 in the resumption of his trial. Patek is the suspected bomb maker of the deadly 2002 Bali bombing. (Photo credit: ROMEO GACAD/AFP/Getty Images)
An Iraqi soldier walks past the debris at the scene of two car bombs close to the governate in the northern oil-rich city of Kirkuk on April 19, 2012, which left several people dead. A wave of bomb attacks in four different provinces across Iraq killed at least 30 people security officials said. (Photo credit: MARWAN IBRAHIM/AFP/Getty Images)
Defence lawyer Vibeke Hein Baera (R) speaks to prosecutor Inga Bejer Engh (L) before Right-wing extremist Anders Behring Breivik arrives in room 250 of the central court in Oslo in Oslo on April 19, 2012. The trial against Anders Behring Breivik charged with committing 'acts of terror' when he slaughtered 77 people in twin attacks in July 2011 that shook the tranquil Scandinavian country to its core got under way Monday, 16 April. (Photo credit: DANIEL SANNUM LAUTEN/AFP/Getty Images)
A Myanmar woman hold a baby street in Yangon on April 19, 2012. The United States invited Myanmar's foreign minister and said on April 18 that democracy icon Aung San Suu Kyi, who is traveling abroad for the first time in decades, had an 'open invitation.' AFP PHOTO / Soe Than WIN (Photo credit: Soe Than WIN/AFP/Getty Images)