Simai Mohamed Said appeared before the party's ethics committee on Tuesday but did not disclose why he had been summoned.

“It is normal to visit the party’s office, and I am not the spokesperson of the meetings, you can find the chairperson or the secretary general of the committee to say something,” Mr Said told journalists immediately after the meeting.

He had resigned as tourism minister two weeks ago, citing "unfavourable and disruptive working conditions".

His resignation has been linked to the alcohol shortage facing the Tanzanian archipelago, which threatens the tourism sector of one of Africa's top travel destinations.

Prices of beer have shot up by almost 100% after the supply chain was disrupted by a sudden change of importers.

Before his resignation, Mr Said publicly accused the Zanzibar Liquor Control Board (ZLCB) of mismanaging the liquor industry.

But Zanzibar’s President Hussein Mwinyi accused Mr Said of having a conflict of interest, while he was the minister.

Reports link one of Mr Said's relatives to one alcohol importing company whose licence was not renewed.

The alcohol shortage comes amid soaring tourist arrivals in the semi-autonomous Tanzanian islands.