A self-taught hypnotist who put a woman under his trance - telling her he was her master and she was his sex slave - has been jailed for 18 months for degrading her.

The 40-year-old grandfather, who had an unblemished record in the services spanning 24 years, had previously pleaded guilty to causing a person to engage in sexual activity without their consent.

Instead of helping his vulnerable victim with weight-loss and anxiety issues, ex-RAF man Timothy Porter took advantage of his skills to make her fondle her breasts.

Porter, of Ouseburn Road, Blackburn, was jailed for 18 months, placed on the sex offenders register for 10 years and banned from contacting his victim and from acting as a hypnotist for 10 years.

Jonathan Walker, prosecuting, said Porter, who served at RAF Leeming in North Yorkshire until the end of 2012, learned hypnosis and offered to carry out hypnotherapy on the married mother, whose identity cannot be reported.

After a series of sessions, Porter turned up at her home on the night of December 2 last year when her husband was away.

Despite her reservations, Porter offered to hypnotise her more deeply than before and the pair sat on a sofa.

"He kept saying, 'No mind, no will of your own'," Mr Walker said.

She became frightened but the session continued.

Mr Walker said: "The defendant stated he was her master, she was his sexual slave."

The amateur hypnotist then persuaded her to expose and touch her breasts.

She was roused from the hypnosis and went to the kitchen, the court heard, and Porter tried to restart the session, without success.

Instead, his upset victim rang a friend, police were called and he was arrested.

Mr Walker said: "His account was that he believed she was consenting to his actions during the course of this incident.

"He agreed the incident had escalated and he misread the situation."

"It has had a profound effect on her sleeping pattern and her general health," he said.