Diplomatic staff with immunity working in the UK have been accused of a string of offences including child pornography and human trafficking.
Diplomats and some employees working in embassies are entitled to diplomatic immunity, which means they can be exempt from being tried for crimes.
According to figures released by the Foreign Office, 11 "serious and significant" offences were allegedly committed by people entitled to diplomatic immunity in the UK last year.
They included an allegation that someone at the Mexican embassy caused a child aged 13 to 15 to watch or look at an image of sexual activity.
Someone at the same embassy is accused of taking an indecent photograph or pseudo-photograph of a child and using threatening or abusive or insulting words or behaviour to cause harassment or alarm or distress.
The figures, contained in a written statement, also show that a member of the Saudi Arabian embassy is alleged to have committed the offence of human trafficking into the UK for the purposes of exploitation, specifically domestic servitude.
A member of the Saudi embassy is also said to have committed the offence of human trafficking for slavery or servitude or forced or compulsory labour.
The figures also revealed that someone at the Gabon embassy was accused of actual bodily harm, while staff at the embassies of the US, China and Kazakhstan have all been accused of driving under the influence of alcohol.
Someone at the Nigeria embassy is said to have driven a vehicle without insurance or an MOT, while a person at the Commonwealth Secretariat is said to have driven without insurance and someone at the St Lucia embassy allegedly caused or permitted the driving of a vehicle without insurance.
In a written statement, Foreign Secretary Boris Johnson said: "In 2015, 11 serious and significant offences allegedly committed by people entitled to diplomatic immunity in the United Kingdom were drawn to the attention of the Foreign and Commonwealth Office by Parliamentary and Diplomatic Protection of the Metropolitan Police, or other law enforcement agencies.
"Six of these were driving-related. We define serious offences as those which could, in certain circumstances, carry a penalty of 12 months' imprisonment or more. Also included are drink-driving and driving without insurance.
"Around 22,500 people are entitled to diplomatic immunity in the United Kingdom and the majority of diplomats abide by UK law. The number of alleged serious crimes committed by members of the diplomatic community in the UK is proportionately low.
"Under the Vienna Convention on Diplomatic Relations 1961, those entitled to immunity are expected to obey the law. The FCO does not tolerate foreign diplomats breaking the law.
"We take all allegations of illegal activity seriously. When instances of alleged criminal conduct are brought to our attention by the police, we ask the relevant foreign government to waive diplomatic immunity where appropriate.
"For the most serious offences, and when a relevant waiver has not been granted, we seek the immediate withdrawal of the diplomat."
It has also been revealed that diplomatic missions and international organisations racked up nearly £500,000 in unpaid parking fines in London last year.
Some 4,858 parking fines were incurred in the capital totalling £477,499, the Foreign Office said.
Following a series of meetings with missions, subsequent payments and waived fines knocked £161,328 off the bill, leaving £316,171 in unpaid fines.
The worst offender was the embassy of the Republic of South Sudan, which owes £53,708, followed by the High Commission for the Federal Republic of Nigeria, which owes £41,531, and the Royal Embassy of Saudi Arabia, which has a debt of £20,692.
The High Commission for the Republic of Zambia owes £18,212, the embassy of the Republic of Liberia owes £13,795, and the embassy of the Republic of the Sudan owes £13,429.
And it has emerged that diplomatic missions owe Londoners more than £95 million in unpaid Congestion Charge fees since it was introduced in February 2003.
Transport for London is owed a massive £95,811,650, with America alone owing £10,626,970 racked up from 89,308 unpaid fines.
This is followed by the Japanese Embassy, which owes £7,072,020 from 59,533 unpaid fines, and the High Commission of the Federal Republic of Nigeria, which has an unpaid bill of £6,045,440 from 50,952 fines.
In total, some 76 embassies owe more than £100,000 in unpaid congestion charge fines, with the figures taken until December 31 2015.