HAVANA - A Cuban court has convicted a dozen people of corruption, including high-ranking government officials, an executive at a state-run nickel company and workers from a project operating under a Cuban-Canadian joint concern, official media announced yesterday.

In a case involving a contract for the expansion of the Pedro Soto Alba nickel and cobalt processing plant at the Moa mine, the sentences range from four to 12 years, the Communist Party newspaper Granma reported.

The court in the eastern province of Holguin took into account "the gravity of these acts and their harmful consequences in one of the strategic activities for the nation's economy, and the conduct of the accused, characterised by the loss of ethical values and deception," the bulletin read.

The announcement was the first official confirmation of a probe that since last year has been the source of rumour and private discussion by diplomats on the island, part of a wider crackdown on graft that has caught up several foreigners and sent a chill through the small foreign business community.

The stiffest prison terms were handed down to Alfredo Rafael Zayas Lopez (12 years), Ricardo Gonzalez Sanchez (10 years) and Antonio Orizon de los Reyes Bermudez (eight years), all former vice ministers at the Ministry of Basic Industry, which oversees nickel production.

Cristobal de la Caridad Saavedra Montero, business director of state-run Cubaniquel, was given six years.

Accounting executive Alfredo Barallobre Rodriguez and deputy production director Orlando Carmenaty Olmo of Empresa Moa Nickel SA.

The Moa Joint Venture that controls the mining operation is operated in tandem by Cuba and Toronto-based mining company Sherritt International Corp, were sentenced to six and five years, respectively.

Sherritt representatives did not immediately reply to phone and email messages seeking comment.

Moa currently produces 37,000 tons of nickel and cobalt per year, according to Sherritt's website.

Six other people also were sentenced. All can appeal.

Two foreign business executives told The Associated Press in November that the same probe had led to the shuttering of Canadian companies Tri-Star Caribbean and Tokmakjian Group as well as the investment firm Coral Capital Group, headed up a Briton.

Two Canadians and a Czech who were reportedly detained in the case were not listed yesterday among those convicted.

Nickel production is one of Cuba's main sources of foreign income, along with tourism. In April a senior government official said the mineral accounted for 30 per cent of exports in 2011, which would put nickel revenues at US$1.8 billion for the year based on recently released overall export figures.