A hate crime officer who was ridiculed for telling shops to use gender neutral signs on for women's sanitary products has been called an "embarrassment" by another officer who suggested he may have abused his powers.

Sergeant Peter Allan was dubbed "Britain's most PC PC" after warning Sainsbury's and Tesco that their signs advertising tampons may breach gender equality rules.

The hate crime and trans equality advocate took photographs of signs for "feminine" products and tweeted the supermarkets' official accounts to complain on 5 August 2016.

In one message, he wrote: "@tesco #FAIL Need to update. Especially with products 4 men on shelf. 'Personal Hygiene' perhaps."

The Sussex Police sergeant also told Sainsbury's: "It’s an issue of gender identity. Men may use the products. Indeed, men’s products were on the shelf. “Personal care” perhaps."

Social media users reacted angrily when the exchanges were highlighted by a Mail on Sunday article.

And one Metropolitan Police officer, who tweets anonymously with the username @ResponseCop, said Sgt Allan's messages were "an embarrassment to the service".

"This idiot is not representative of the wider Police Service across the country," he said.

"No common sense & likely all just for promotion. Ridiculous."

While the officer, who has served for six years, supported Sgt Allan's aim to promote equality and diversity, he said the messages about tampons represent "political correctness gone mad".

When Twitter user Steve Ludek asked if Sgt Allan had used his position to "scare" Tesco, @ResponseCop replied: "Might be worth sending a complaint to his force about perceived abuse of power via social media and unprofessionalism."

Sgt Allan faced further criticism for tweeting about a hate incident that involved "name calling between children" on 8 August.

Firefighter @MrsFireyFairy, who describes herself as the "proud wife of a Met Police Officer", tweeted: "On a serious note @SgtPeterAllan has undone yrs of good work by others fighting for the LGBT community & made a mockery of issues they face."

Despite being relentlessly mocked online, Sgt Allan's efforts to promote LGBT issues have won some praise.

On 8 August, transgender campaigner @mimmymum tweeted: "@SgtPeterAllan is my hero of the day! Just knowing the police take #trans #hatecrime seriously is reassuring."

Sussex Police chose not to comment on the Twitter exchanges with Tesco and Sainsbury's, and Sgt Allan couldn't be reached for comment.

He recently spoke out after Paul Pawlowski, 90, was convicted of racially aggravated harassment for displaying an anti-Semitic placard in Burgess Hill, Brighton, on 28 May.

Speaking after Mr Pawlowski was ordered to pay fines and costs of £335, Sgt Allan said: "People have a right to free speech, but hate speech will not be tolerated.

“If hate speech is not challenged appropriately, it can lead to communities feeling a sense of unease and can send a message to perpetrators that such behaviour is acceptable.

“This sentence sends out a clear signal that we will take a robust approach to those who target individuals based on their disability, gender identity, race, religion or sexual orientation. I hope this case will encourage other victims of hate to report such behaviour to the police.

“We will record all such incidents and take them seriously. We will investigate any allegations, irrespective of the age or any other demographic of those involved.