Two men claiming to be from the South African Revenue Service (Sars) walked into the home of prominent unionist Patrick Craven and stole three laptops and an iPhone.

Craven said that, around midday on Wednesday, he was visited by two men who claimed to be officials from Sars.

"They claimed that they had been sent by Sars to visit people whom they owed money to. While I was speaking to the one man, unbeknown to me, the other man walked around and took three laptops and an iPhone."

Craven said the men were very pleasant and he did not feel threatened in any way.

"I was by myself when the men came to my house."

He said he had opened a case with the police.

"It is one of two things, it is either that it was a genuine criminal act or people looking for information. People in the trade unions have been victims of theft. My suspicion is that it could be political and people are looking for information."

South African Federation of Trade Unions general secretary Zwelinzima Vavi tweeted: "Crooks probably state security agents for the third time now in recent years, have stolen @PatrickCraven1 laptops! They pretended to be from Sars and knew that Sars owns him some money! They pretended to be doing lifestyle audit. Two laptops & cell gone. [sic]

"This has the hallmarks of a co-ordinated assault on media freedoms."

Speaking to News24, Vavi said Craven had only realised that he had been robbed when the men had left.

"They are so obsessed with getting information. Now we have to sleep with our laptops under our pillows," he said.