Allegations that Married at First Sight Australia stars were not told about their on-screen partners' previous drug and violence convictions are "serious and disturbing," the country's media watchdog has said.

The claims, reported in a BBC News investigation on Saturday, have also prompted a response from the UK's media regulator Ofcom, who called them "deeply concerning".

Several male contestants have been allowed on the show - known to many as MAFS Australia - despite having been convicted of, or having faced allegations of, violence, assault or drug use.

The Australian broadcaster Channel 9 and production company Endemol Shine Australia, which makes the show, have said they have "strong protocols in place to ensure participant safety and wellbeing".

As well as being a huge hit in Australia, the show is popular in the UK and is shown on Channel 4.

Channel 4 has pulled all the UK episodes of MAFS from its streaming service All 4, but MAFS Australia remains available to watch.

It comes after the British version of the show was plunged into crisis after BBC Panorama reported rape allegations from two women contestants - allegations the men involved have denied.

Channel 4 has commissioned an external review into contributor welfare on MAFS UK which is due back later this summer.

MAFS UK is made by a different production company to the Australian version.

Nine MAFS Australia stars told the BBC they wanted the show to improve its background checks and to stop allowing individuals with previous convictions on the show.

Reacting to our investigation, a spokesperson for the Australian Communications and Media Authority (ACMA) told the BBC it "acknowledges the serious and disturbing matters" raised by former participants on the show.

The regulator said that its jurisdiction is limited to investigating whether content that has been broadcast complies with the relevant industry codes of practice.

It is understood that there are no provisions about the treatment of programme participants in those codes of practice.

The spokesperson added: "When members of the public raise concerns with the ACMA that fall outside of our regulatory remit, we encourage them to bring those concerns to the broadcaster and, where appropriate, to the relevant authority."

Echoing the Australian regulator, an Ofcom spokesperson said: "These latest allegations are deeply concerning and we would expect Channel 4 to take account of them in its ongoing reviews into contributor care.

"We await its findings which we will consider alongside all other evidence made available to us."

Both the UK and Australian versions of MAFS show single people agreeing to "marry" total strangers after meeting for the first time at their mock weddings.

The marriages are not legally binding, but viewers see the couples go on "honeymoons", before moving in together and navigating their relationships - all while being filmed, almost every day.

In a joint statement responding to the BBC's investigation on MAFS Australia, Channel 9 and Endemol Shine Australia said they take their obligations in respect of the health, wellbeing and safety of participants "extremely seriously".

"There is a structured, multi-stage checking process that every participant must complete and clear," they said - including police and criminal-history checks in each declared country of residence, independent clinical psychological assessment, medical screening, disclosure supported by a statutory declaration, and legal and digital due diligence.

Channel 4 has said it is not involved in the production of MAFS Australia and has "no editorial control or input" into its making.

"However, Channel 4 ensures any version it transmits of acquired programmes adheres to the Ofcom Broadcasting Code."