The former jockey and trainer had originally been serving a 10-year ban from Britain's 59 racecourses for horse-doping offences.

He appeared at Portman Square in relation to allegations that he doped horses between 3 August and 20 September, 1990.

But before he left, the former jockey and trainer handed in a letter which could contain some of racing's darkest secrets.

"There are still people involved in racing who I know have been involved in corruption, generally in racing, some high-profile," he said afterwards

Browne, son of leading Irish trainer Liam Browne, was first warned off by the Jockey Club in 1992 and has not been seen at a racecourse in Britain since.

But that ban officially lapsed last month when an interim suspension was imposed.

He was not surprised by the outcome of the hearing, but did leave a letter for the attention of Jockey Club executive director Christopher Foster.

Browne told BBC Five Live he knew of a leading racing personality, who cannot be named for legal reasons, who was corrupt.

He added: "I came here today to draw this to an end. It's something that has been going on a long time.

"Everything is straightforward. I breached the Rules of Racing and I admitted that.

"There are an awful lot of very hard working and honest people in racing.

"I got involved with some of the wrong ones. Sadly there are still some out there now."