An 80-year-old peace campaigner arrested at a protest march has threatened to sue Sussex Police.

Veteran activist John Catt claims officers left him in agony by forcing his arms behind his back and marching him up North Street in Brighton.

His shorts fell down around his ankles as he was being handcuffed by officers.

Mr Catt, of Withdean, Brighton, said: "It was a thoroughly humiliating and painful experience. I was cuffed near the Clock Tower with my shorts down, unable to pick them up, in front of hundreds of people.

"I feel I was brutalised simply for expressing my opinions."

Mr Catt, a widower, was one of four people arrested for alleged public order offences during the march in August, which brought parts of Brighton to a standstill.

He was locked up for several hours at the police custody suite at Hollingbury.

Mr Catt, who refused a police caution and was eventually released without charge, said: "I was taking part in a legitimate, peaceful campaign on an issue I feel strongly about.

"The police know me because I have been attending protest marches for years.

"A few scuffles broke out but I was nothing to do with them. I am 80 years old and although I'm in good shape I'm opposed to violence.

"A police office cherry-picked me out of the crown and I was hauled away.

"Now I'm considering suing the police for wrongful arrest, wrongful detention and damages."

The demonstration was organised by campaign group Smash EDO as part of its protests against an arms components factory in Home Farm Road, Moulsecoomb, Brighton.

It was attended by a few hundred campaigners and 50 police officers.

It was the third demonstration since an interim injunction was granted banning campaigners from harassing members of staff at EDO and entering an exclusion zone around the factory.

War veteran Mr Catt, whose home overlooks Withdean stadium, is no stranger to legal action. Earlier this year he successfully challenged the legality of Brighton and Hove Albion's planning permission to play at Withdean and add 2,000 extra seats.

The former trade unionist has regularly protested against EDO and is a life-long campaigner against war, racism and injustice.

A police spokeswoman said: "John Catt was arrested on suspicion of obstructing the highway and obstructing a police officer."