LINDA

LINDA (London Investigative ' N Detective Agency) was a secret organisation founded in early 2007, and broken up in the spring of that same year with the murders of most of its members. It was a society dedicated to finding out about the mysterious "Doctor", composed of five people - Elton Pope, Ursula Blake, Mr Skinner, Bridget Sinclair and Bliss

All but Elton were absorbed by the Abzorbaloff, but Ursula was later partially returned from the dead by the Doctor's sonic screwdriver in the form of a face embedded in a slab of concrete. (DW: Love & Monsters)

The Doctor himself became aware of LINDA's activities before or during his fifth incarnation (at which time he appeared to find them slightly embarrassing). (DW: Time Crash)
 * As the Fifth Doctor doesn't know all members of LINDA it seems that the organization, or a new one using the same name, had a revival with more members.

However, he made no attempt to contact them until after Elton Pope befriended and then upset Jackie Tyler, which in turn angered Rose. (DW: Love & Monsters)