A Thai government worker has been arrested for allegedly having sex with the same stray dog for more than a year.

The 59-year-old civil servant, whose name was not disclosed by police, was reportedly caught dragging the female mutt into the toilet stall of a public park in Songkhla, southern Thailand.

Animal rescue volunteer Surachet Sorawitnatchayakul confronted the man after he emerged from the graffiti-riddled cubicle with his belt unbuckled and his zipper undone on August 25.

Footage shows the suspected animal attacker, seen wearing a striped polo shirt and shorts, arguing with Surachet as he allegedly admitted he had 'raped a dog'.

He then tried to punch the shocked passer-by before fleeing the scene - a remote area frequented by pensioners for exercise.

Surachet said: 'I've seen that man riding a motorcycle around the park many times.

'Around six months earlier, I learned from a nearby food vendor that he'd been abusing stray dogs for a long time.

'I investigated and learned that he had been doing this to the same dog for a year. He was returning to it multiple times.

'I didn't want to get involved at the time but I kept seeing him in the park, and realised he was doing the same thing, so I decided I would find the right time to catch him.'

The Good Samaritan submitted the footage to Wanyanee Suwanchatree of animal welfare charity Watchdog Thailand Foundation, who then filed a report at the local police station.

Wanyanee said: 'A summons has been issued for the man involved in the incident. He is a 59-year-old civil servant in a government agency, who is retiring this September. Based on the evidence, we are confident he will face imprisonment and a fine.

'The investigation revealed that the man had been sexually assaulting dogs for years, but there was only unclear photographic evidence because the park was quiet and had few visitors. However, this time, a video clip has been recorded.

'I will also write a letter to the suspect's superiors, as the organisation where he works is reputable and his actions may damage their reputation.'

Bestiality is a form of animal cruelty under Thailand's Prevention of Cruelty and Animal Welfare Provision Act 2014, which includes 'using of disabled, ill, aged, or pregnant animal for exploitation, for sexual activity'.

Violating the act is punishable with up to two years in prison, a maximum fine of 40,000 Baht (915 GBP), or both.

(1 GBP = 43.72 THB)