Colombian police chief Gen Rodolfo Palomino has resigned a day after the prosecutor general said he would open a «disciplinary investigation» into allegations Gen Palomino created a male prostitution ring within the force.
The general is also under investigation for alleged illicit enrichment and conducting illegal wiretaps.
Gen Palomino said he had asked President Juan Manuel Santos to be allowed to retire.
He said he was «absolutely innocent».
Gen Palomino served in the police for 38 years and was made director-general of the police force two-and-a-half years ago.
Standing next to his family, he said that he was «not guilty of any of the charges levelled against me» and that he was confident the investigation would clear his name.
The investigation was triggered by allegations by a police captain who said he had been abused by higher-ranking officers during his time as a cadet.
Colombia’s prosecutor general, Alejandro Ordonez, said that allegation had been backed up by a complaint by a now retired police captain.
According to the complaint, young male police cadets were cajoled and threatened into having sex with higher-ranking officers.
Mr Ordonez said that according to the testimony gathered by his office, a senator had also allegedly been implicated in the prostitution ring, called «Community of the Ring».
He also said that the alleged incidents had taken place «with the help and complicity of police officials, including the director general [Rodolfo Palomino]».
The wiretapping accusations also relate to the case. Police officers allegedly tapped the phones of journalists investigating the scandal.
Analysis: Natalio Cosoy, BBC Mundo, Bogota
Although the prostitution ring allegations emerged a few years ago, it was the radio journalist Vicky Davila and her team at La FM Radio who brought them to wider attention in the last few months of 2015.
I met her and one of her colleagues, Juan Pablo Barrientos, in December, when she told me how an anonymous source contacted her via email to tell her she was being followed and her conversations tapped.
Mr Barrientos told me how on one occasion he was working on his computer on a story about Gen Palomino when he suddenly saw the cursor deleting everything he had written.
Attorney General Eduardo Montealegre confirmed in December that Ms Davila and her team were being wiretapped and spied on by Colombia’s National Police. But he also said that Gen Palomino was not being investigated in connection with the wiretaps, involvement in which he has always denied.
Gen Palomino has all along denied any wrongdoing.
He has also denied allegations of illicit enrichment and has provided prosecutors with documents which he says show where his money and properties come from.
He said the allegations were a political vendetta designed to drive him out of office.