LONDON — A man has been arrested in connection with the killing of a British police officer by a gunman who opened fire from inside London's Libyan Embassy more than three decades ago.
Constable Yvonne Fletcher's was killed as opponents of then-dictator Moammar Gadhafi protested outside the diplomatic site on April 17, 1984. Her death sparked a 11-day siege of the building and the severing of U.K.-Libya ties.
A Libyan man aged in his 50s was arrested in southeast England on conspiracy to murder offenses, according to the Metropolitan Police.
"This is the first significant arrest in this investigation," Richard Walton, who leads London police's counter-terrorism command, told reporters on Thursday.
The Libyan was also arrested on suspicion of money laundering, along with a woman in her 40s and a man in his 30s, according to police. None of those detained was identified.
Searches were ongoing across the U.K., police said.
Fletcher was 25 when she died after shots were fired from inside the Libyan Embassy — including some from an automatic weapon, according to police. Ten Libyan men who were protesting Gadhafi's rule were also shot and injured.
British officers made seven visits to Libya to investigate Fletcher's murder after the fall of Gadhafi in 2011. As a result of the trips, police believe there was a conspiracy to murder officers and opponents of the regime and that participants of a pro-Gadhafi rally being held at the same time got instructions from within the embassy.
Walton appealed to any Gadhafi supporters who were outside the Libyan Embassy "to rack their consciences and come forward with any information they might have."
Police also offered a $76,000 reward for information leading to the capture and prosecution of those involved.
"We are also issuing footage from the demonstration moments before the fatal shooting and reaching out to Libyan communities in the U.K. and other countries through social media urging anyone with information to come forward," according to the police statement.