Members of Qatar’s ruling family are reportedly launching a fresh lawsuit against HSBC Suisse Bank for some $2.6 billion dollars in a dispute that apparently goes back 30 years.

Those undertaking the legal action are the heirs of Khalifa bin Ali bin Abdullah al-Thani, whose brother Ahmad bin Ali al-Thani ruled as the emir of Qatar from 1960-1972. In short, they haven’t been given access to the money they say is there.

(They are not direct relatives to the current emir, Hamad bin Khalifa al-Thani, as his father was the cousin of Ahmad and Khalifa bin Ali.)