Doreen Lawrence, the mother of murdered teenager Stephen Lawrence, demanded answers today after meeting Home Secretary Theresa May and called for an open inquiry into claims police tried to smear her family.
Speaking outside the Home Office afterwards, she said Mrs May had told her "all options are open".
Mrs Lawrence was accompanied by her surviving son Stuart and her lawyers Imran Khan and Michael Mansfield QC.
She wants a public inquiry into the claims by a former undercover officer that her family were targeted between 1993 and 1997.
Earlier this week Mrs May said the claims could be investigated by two existing inquiries - a police probe into the activities of undercover officers and another led by Mark Ellison QC into allegations of corruption in the original investigation into Stephen's murder.
Mrs Lawrence said: "She said all options are open and she explained about the different reviews that are going on at the moment and how it could be expanded.
"I made my point quite clear. For the past 20 years the fact that we as a family have been talking about corruption and we have undercover officers trying to smear our family. I want answers. I want to know who was the senior officer who signed that off.
"We had no idea this was going on from 1993 until 1997."
Stephen's father Neville has called for a judge-led inquiry into the claims, claiming that the current investigations are not enough to get to the truth.
Mrs Lawrence said: "We want it to be open and not behind closed doors, so that we can hear once and for all exactly what was going on after Stephen was murdered.
"Over the years with what we've talked about and how we've been trying to get to the truth around Stephen, I don't think anything can give us that unless it is out in public.
"I think unless we have a public inquiry and go through the whole thing we will never get to the bottom of it."
She said she does not trust the existing police-led investigation into undercover officers and expressed her shock at the claim that her family was targeted.
"I felt sick to the stomach because it was not what I expected. We thought that we'd heard everything. This is just the tip of the iceberg now."
Mrs Lawrence and her legal team will meet again with Mrs May, but they have not yet been given a date.
Mr Khan said the family want the inquiry to primarily look at the claims affecting their family, but also the activities of undercover officers more generally.
Yesterday Mr Mansfield said the family want either a public inquiry like that led by Lord Justice Leveson into malpractice by journalists, or an independent panel similar to the one that examined the Hillsborough disaster.
He said: "One of these two has got to happen. Not another internal inquiry which will not be made public because they will claim it's sensitive information.
"It doesn't necessarily have to take particularly long, Leveson was done in a year and it's a good example of something that was done in public and quite searing questions were asked. Hillsborough was very efficient too.
"We're not talking about a public inquiry that takes years and a report that gets left on the back burner, we're talking about an efficient, focused inquiry."
Additional claims emerged this week that police had bugged meetings between officers, lawyers and Stephen's friend
Duwayne Brooks, who was with him on the night that he was murdered by a racist gang in 1993.
Mr Mansfield, who represents the Lawrence family with fellow lawyer Imran Khan, said: "I'm wondering if they did exactly the same with Imran and myself. I will want assurances that they have not done that. It's a very serious situation.
"This has been a very sorry saga. Doreen has been extraordinarily patient." The claims emerged after ex-undercover officer Peter Francis, who worked with Scotland Yard's former Special Demonstration Squad, decided to speak out about the campaigns he had been told to infiltrate in the 1980s and 1990s.
Greater Manchester Police said they were also looking into claims that the force's Special Branch sent a memo in August 1998 to all divisions seeking information on "groups or individuals" expected to attend the Macpherson inquiry into the police handling of the murder case.
Charles Crichlow, president of the National Black Police Association, told The Mirror the note "sent a chill through me" when he read it at the time. GMP Deputy Chief Constable Ian Hopkins said officers were trying to trace the memo but added that it was likely to be a "routine" note referring to the arrangements for the policing of the inquiry, which was held in Manchester.
A Home Office spokesman said: "The Home Secretary is grateful to Doreen and Stuart Lawrence and their representatives for coming to the meeting today.
"The Home Secretary understands that these fresh allegations have only added to the suffering of the Lawrence family. She will now reflect on the best and quickest way to get to the heart of all outstanding questions and will speak to the Lawrence family very soon."