Two suspected Special Forces officers have been arrested on suspicion of breaching the Official Secrets Act.
The men, aged 33 and 35, were detained in early March at around the same time that a number of Special Forces officers were deployed to Libya to make contact with rebels and gain information on stranded British oil workers.
It is not clear at this stage what information the men are suspected of leaking.
The arrests took place shortly before eight men, six reportedly SAS, were detained by rebels in the Port city of Benghazi.
The team was later released with Foreign Secretary William Hague telling the Commons that the detention by the rebels of the eight-strong group - thought to include at least one MI6 officer - had been the result of a "serious misunderstanding".
A Metropolitan police spokesman said: "On the evening of Wednesday, March 2 2011, MPS officers arrested two men aged 33 and 35, on suspicion of breaching the Official Secrets Act 1989.
"Both men were taken to a central London police station.
"On Thursday, March 3 both men were bailed to return to a police station. They are bailed to return on dates in May.
"Four searches were carried out in connection with the arrests."