Catalan Police chief Josep Lluis Trapero is to be investigated for sedition by the National High Court in Madrid, El Español reported on Wednesday morning.

The newspaper said the chairmen of the Catalan National Assembly, Jordi Sánchez, and Òmnium Cultural, Jordi Cuixart, will be investigated for the same crime.

El Confidencial reported all three men must appear before the judge in Madrid on Friday.

The summons are not related to King Felipe's statement on Catalonia on Tuesday night but to an investigation into the events of September 20, when up to 40,000 people, according to the Public Prosecutor's Office, prevented court staff and judicial police (Civil Guard) from leaving a building in central Barcelona whilst carrying out a search.

ANC chairman Sánchez was joined by Cuixart during that demonstration, said the prosecutor on September 22, and "they called for 'permanent mobilisation' from this Thursday in favour of the referendum and against actions to stop it".

The original investigating judge had to phone Catalan Police chief Josep Lluis Trapero in person shortly after 10 p.m. "to order him expressly" to protect judicial staff and Civil Guard officers and allow them to leave.

The Deputy First Minister of Catalonia, Oriol Junqueras, said on Twitter that the three were being "investigated for obeying the will of the people of Catalonia", and offered them support.