The Clarkes became drug runners on cruises from the Caribbean to Europe, but came unstuck because Roger bragged. Photo / Facebook

Cocaine-smuggling grandmother Susan Clarke has died in agony in a rat-infested Portuguese jail where the 72-year-old was serving eight years for trafficking on a cruise ship with her husband.

Clarke, who died on Sunday, was allowed one last visit from husband Roger, 73, four weeks before she died in pain from breast cancer which Portuguese prison doctors had ceased treating.

The British woman, who shared a 3m x 3m cell with three other women, died behind bars at Portugal's maximum-security prison EP Tires in Sao Domingo de Rana, west of Lisbon.

She had been incarcerated there since police acting on a tip-off found 9kg of cocaine in the linings of four suitcases the Clarkes had on the luxury Marco Polo cruise liner.

The couple were arrested as the Marco Polo liner sailed into Lisbon from the Caribbean in December 2018.

Susan and Roger claimed they thought they were smuggling exotic fruit after Roger picked up the suitcases when the ship stopped at the paradise island of St Lucia.

However the pair, from the southeastern English town of Chatham, Kent, who have eight grandchildren, had earlier been caught smuggling 240kg of cannabis into Norway in 2004.

It is believed they carried out multiple smuggling trips before a sniffer dog detected drugs in their battered old Nissan in Oslo.

They skipped bail and changed their names from Button to Clarke, but were eventually extradited and served time in a Norwegian prison.

The former truck driver born Roger Button and his wife had tried to reinvent themselves as respectable British expatriates living in Spain.

But it is believed they worked for a Costa-del-Sol British drugs gang, regularly smuggling cocaine into Europe on up to six cruises a year they never quite explained to friends and family.

After their 2018 arrest, the Clarkes were locked up in separate Portuguese jails.

Susan found a lump in her breast in early 2020 and was diagnosed with cancer, but had reportedly been due to be transferred back to a British prison to finish her term.

The UK Mirror reported that four weeks ago, Susan was given one last visit with Roger and that "they saw each other through a Perspex window".

"She was handed a life sentence – left to die in a foreign prison with no loved ones around her," the source said.

"She had a lump in her throat which meant she couldn't actually speak.

"She was battling breast cancer but the doctors in Portugal decided that there was nothing they could do for her, so they stopped her treatment.

"She was in so much pain. Roger seems to think they had won a battle to come back to the UK to, so he's devastated that she wasn't well enough to make the move."

The Clarkes last drug mission came to grief, allegedly, because Roger boasted to cruise ship friends.

After leaving the ship for the island of St Lucia, he returned with four new suitcases and "took them straight to his cabin".

He reappeared on the pool deck "bragging" about having done "a really good deal, 200 dollars for four suitcases" which would have cost the equivalent of 1500 British pounds or almost $3000 in Harrods.

He gave one of his old suitcases to a cabin boy and then crew gossiped about how they'd never seen anyone "swap suitcases mid-journey".

Roger was known to brag over drinks which the couple enjoyed nightly on the cruise before police swooped.

During their court case in Lisbon, Roger Clarke claimed he was taking the suitcases back to the UK for a friend who planned to sell them for profit to up-market stores such as Harrods.

When sentence was passed, Roger was holding hands with his wife in court as an interpreter announced their fate.

He allegedly whispered to her: "Jesus Christ, I was not expecting more than four years. I'll be 80 when all this is over."

Portuguese prosecutors said they estimated the Clarkes were making up to $50,000 per cruise smuggling drugs into Europe.

They believed the couple had been planning to offload the cocaine in the UK.

After falling ill with cancer in prison, Susan Clarke, a former secretary, lost at least 15kg and feared she wouldn't make it out of prison alive.

"My health is terrible," she said.

"I've been handed a death sentence. My worry is I'll be leaving in a box."

"We feel completely abandoned. The Foreign Office has ignored us, Boris Johnson has not helped.

"I can understand why people might believe we are guilty but we are not."

Roger Clarke has now been transferred from his cell in the EP Lisboa jail to a lower-security facility.

The UK Foreign Office said: "We are supporting the family of a British woman who died in Portugal.