Ms Fletcher was shot dead outside the Libyan embassy in St James’ Square back in April 1994. The shots are believed to have been fired from inside the embassy building, and no one has ever been charged for the murder.

Staff inside the embassy claimed diplomatic immunity, and were all deported from the UK. PC Fletcher’s death sparked an 11 day siege on the Libyan embassy.

Diplomatic ties were then severed between Britain and Libya.

The investigation by British police has been ongoing ever since, and a Metropolitan police team is set to fly to Libya to look for answers.

Mr El-Keib was seen bowing to the memorial erected for PC Fletcher after her death as he laid the wreath there. He was exiled from Libya during Colonel Gaddafi’s rule, and has been installed as Prime Minister temporarily, until elections can take place in the North African country.

He has promised to “work very closely” with British police, to help with the investigation and find who killed PC Fletcher.