French and British operatives have been working with Libyan rebels on their eastern front, where the insurgents scored strategic blows against Muammar Gaddafi's forces.
The operatives are installed at the rebel command for the eastern front, at the dysfunctional oil refinery in Zuwaytina, about 150 kilometres (93 miles) southwest of the opposition capital Benghazi.
They are equipped with telecommunications equipment and housed in two shipping containers, within walking distance of the headquarters of Fawzi Bukatif, commander of the eastern front.
He has been working out of a large office with walls covered in maps and satellite photos.
There are at least two Frenchmen, and several Britons in mismatched camouflage outfits, an AFP reporter said.
In late April, Britain, France, Italy, Egypt and the United States announced that they had sent military advisers to the National Transitional Council, the rebels' de facto government.
The Daily Telegraph today quoted British defence ministry sources as saying SAS members were sent to Libya several weeks ago and played a key role in coordinating the battle for Tripoli, which the rebels overran on Sunday.
Camouflaged in civilian clothes and armed with the same types of weapons used by the rebel forces, the commando members have been tasked primarily with finding Libyan strongman Muammar Gaddafi, the paper said.
Britain's defence ministry has declined to comment on the report.
The rebels who overran the Libyan capital and capturedGaddafi 's Bab al-Azizya compound on Tuesday, have offered a $1.7 million reward for the capture of the elusive strongman, dead or alive.
The Zuwaytina refinery served as the rebel headquarters while directing weeks-long battles for the key oil hub of Brega, 90 kilometres to the east, where the insurgents scored a knockout blow against pro-Gaddafi forces in an operation backed by NATO air strikes.
After the rebels stormed Tripoli on Sunday, Gaddafi's forces retreated more than 100 kilometres to the west, stopping at the town of Bin Jawad, 140 kilometers (87 miles) east of the port of Sirte,Gaddafi 's hometown and his last remaining bastion.
Bukatif is preparing to move his operational command from Zuwaytina to the town of Ras Lanouf, about 20 kilometres (12 miles) from Bin Jawad.