Traffic was held up for much of Tuesday as panic-buying drivers created mile-long queues in petrol stations.
Motorists across the UK rushed to filling stations on Tuesday to stock up after the presenters on Cardiff-based Red Dragon FM's drive time show mentioned rumours that another fuel blockade was looming.
Managing director Beverley Cleall-Harding said the programme had been responding to calls from worried listeners.
After examining a transcript of the Monday evening show, the broadcasting watchdog the Radio Authority, has decided that the station has not been guilty of scaremongering.
"When rumours reach the level this rumour reached, it is always difficult for an information medium, particularly one as powerful as radio, to address it without perpetuating it," said a spokesman for the authority.
The rumours of a strike by tanker drivers quickly led motorists to form long queues at petrol stations across Wales.
Traffic was held up for much of Tuesday as panic-buying drivers created mile-long queues in petrol stations.
The rumours spread quickly around Britain - partly through e-mails - and eventually forced Labour's Margaret Beckett to repeat that there was no substance to them.
Unnecessary problems
A spokesman for the Texaco refinery in Pembroke Dock said tankers were leaving as normal and there were no protests.
Police forces around Wales appealed for motorists to remain calm and not panic-buy.
They said there was no information or intelligence to support the rumours, and filling up would just cause unnecessary problems and inconvenience for motorists themselves.
But one Tesco filling station in Cardiff was forced to close because of the traffic problems caused by queueing drivers - not because of a fuel shortage.
One of the leaders in last week's blockades, north Wales farmer Brynle Williams, said he was "totally amazed" by the rumours.
He said the protestors were sticking to their 60 day deadline for the government to come up with cuts in tax on fuel.
The rumours came a day after First Secretary Rhodri Morgan said he expected petrol prices to fall in the wake of the fuel blockades.
Mr Morgan was speaking after the first meeting of the government taskforce set up to find ways of preventing a repeat of the fuel crisis.
Home Secretary Jack Straw, who heads the taskforce, told Monday's meeting that while discussions continue on new legislation, he would be seeking a "memorandum of understanding" with the oil companies setting out both their and the government's obligations in the event of another crisis.
Crisis
After the meeting Mr Morgan said he expected the chancellor to announce in November a package of measures to bring down fuel prices in next March's budget - if the cost of crude oil does not come down beforehand.
The taskforce's first meeting was overshadowed by allegations of collusion between the oil companies and the protestors during last week's protests.
But the allegations from the TGWU union were refuted by one of the Welsh protestors at Pembroke Dock.
"We had a fantastic relationship - no problems at all," said haulier Mike Green.
Across Wales services have returned to normal in the wake of the crisis which saw ambulances answering only 999 calls and schools closed.