ACT Fuel Watch, which gained close to 20,000 social media followers in just six months, documented the cheapest prices across the territory and provided analysis of trends.

In a statement, the founders of the group said they decided to stop posting petrol prices on the page due to time restraints and concerns about their work.

"We cannot invest the time needed to sustain the arguments and ongoing conversations around the legality of what we are doing, or the risks associated," said founder Benjamin Ling.

"As you all (most) are aware, we are a very small team but we are happy with the milestones that we have made along the way to transparency in the ACT market."

The group began posting petrol process online in January due to frustration at ACT drivers paying more for fuel than motorists interstate or on the other side of the territory.

"In some instances there was 30c difference between the same brand of station on one side of the ACT to the other," said a statement on the group's website.

"We stepped in made the information of fuel pricing transparent and available with a Facebook page ACT Fuel Watch."

Mr Ling he would work with ACT Fuel Watch co-founder Rohan Aldridge to launch an email subscription service for those who wish to continue receiving updates on petrol prices.

The initiative received an endorsement from ACT Chief Minister Andrew Barr, who said it "showed the power of a grassroots effort by Canberrans to get a better deal".

In December 2014, Mr Barr wrote to the Australian Competition and Consumer Commission boss Rod Sims seeking an investigation into the higher prices Canberra motorists pay compared to drivers in other capital cities.

In a statement, ACT Fuel Watch said it was proud it introduced transparency to the fuel market and hoped petrol stations would "never again be able to hide behind the fog of information".

"Over the six months that ACT Fuel Watch and our nearly 20,000 supporters have been active, we have had a vocal mix of support and criticism, on and off the field."