A British Transport Police inspector has been dismissed at a misconduct hearing for having sex while on duty.
Insp Masood Khan met the woman through a dating website
Inspector Masood Khan, 42, of Coulsdon, south London, admitted having sex with a 43-year-old woman in an office at Gatwick Airport railway station.
He was found not guilty of wilful misconduct in public office at Southwark Crown Court last August.
The Independent Police Complaints Commission said his actions had brought the police service into disrepute.
Mehmuda Mian Pritchard, who managed the IPCC investigation, said the police service and the public "had a right to expect the highest standards of conduct from officers".
He added: "Masood Khan's behaviour is not of a standard we expect of an experienced officer.
"His actions have brought the police service into disrepute and ridicule and the panel has recognised this."
Insp Khan met the woman through a website for people who want to find dates with people in uniform, Southwark Crown Court was told.
CCTV footage from the station showed the pair going into a small office at the end of one of the platforms and emerging 20 minutes later on 23 July 2006.
The inspector, who had been an officer for 15 years, said in court: "It was absolutely the wrong thing to do, morally and professionally. I should never have done it."
The jury heard he was the most senior officer on duty on the south east rail network and had a team of 20 officers serving under him.
Mr Khan said he had kept in contact with his office by mobile and radio during the sex session.
He was suspended from his job two days later.
After the misconduct hearing on Tuesday, a British Transport Police (BTP) spokesman said it expected "the highest standards of behaviour" from its police officers and staff.
"We take all misconduct seriously and it is thoroughly investigated - in this case the investigation was managed by the Independent Police Complaints Commission," he said.
"Inappropriate behaviour inevitably tarnishes the good reputation of the organisation, which has been built up by the hard work and commitment of a great many people.
"We sincerely hope that this isolated incident will not adversely affect the confidence the public have in BTP."