The overwhelming majority of advertising breaks broadcast during football matches in Britain featured at least one gambling advert, a new survey has shown.

According to the BBC's Victoria Derbyshire show, one in five of the commercials broadcast across 25 football matches this season were for betting firms, while the ratio was as high as one in three for some games.

Overall, 95% of the games analysed, which were broadcast across Sky Sports, BT Sport and ITV, featured advertising breaks contained one advert for a bookmaker.

Everton's Europa League match against Apollon Limassol on 28 September on BT Sport, saw 40% of the adverts and sponsorship idents were for betting, with 18 adverts for five firms.

Meanwhile, during Sky Sports' broadcast of Scotland's 3-0 defeat by Slovakia on 11 October last year, 37% of the commercials were betting-related, with 19 gambling adverts for eight different firms.

Commercials for betting campanies can not be shown on TV before the 9pm watershed, but live sporting events are exempt from the agreement. However, earlier this year, Australia banned all betting ads before the watershed even if broadcast during sporting events, an approach which has recently been adopted in Belgium.

But betting firms are a major contributor to the coffers of Premier League and Championship clubs.

A single advert during a Premier League fixture is thought to cost approximately £35,000 and gambling firms spent approximately £150m on TV adverts last year alone. Of the 20 Premier League clubs, nine are sponsored by a gambling or betting firm and a recent study by Goldsmith University found approximately 250 ads for gambling and betting firms were shown during Match of the Day.

"We are concerned about the effects of children and young people being exposed to gambling advertising due to the pre-watershed exemption for live sporting events," said Matt Zarb-Cousin, from the Campaign for Fairer Gambling. "The government has an opportunity to address this in the forthcoming review."

The Department for Digital, Culture, Media and Sport is indeed expected to release a review on the sector either this week or early next month, which could place tougher restriction on the broadcasting of betting ads.

The government has previously pointed out that it "expects the gambling sector to protect players" but it has also admitted that "clearly more work is needed" to ensure gambling ads are regulated.