LAWYERS have criticised plans to have the Tweed courthouse in a separate building to the new Tweed Heads police station.

Tweed MP Geoff Provest said plans for a single building, to house the police station and court were scrapped in favour of two separate buildings so the courthouse could be bigger.

The courthouse would have two courts - one potentially a district court - and 24-hour correctional services.

But prisoners will have to be moved in correctional services or police cars unless, as Tweed Byron Local Area Command Inspector Gary Cowan put it, "they build a tunnel".

Crystal Creek lawyer Phillip Mulherin said the current plans were "unsafe" and "inefficient".

"The two services should stay together for the security of staff; witnesses ... domestic violence support people, MERIT (Magistrates Early Referral into Treatment) people and parole people.

"It's also about efficiency. There will be so much wastage of police time, moving prisoners to and from court," he said.

Tweed solicitor Russell Baxter, a former police officer, agreed. He said when Sydney's Central and Waverly courthouse and station were de-centralised the force went through "a huge turmoil".

But Mr Provest said he had the support of the Police Association and Attorney General's office. He also said re-planning would take another two years.

NSW Police Association's Brett Henderson said for current plans to work, Corrective Services officers must be available full time, so police aren't pulled off the beat for prisoner transfers.

"Ideally we'd like (the courthouse and police station) connected, but realistically it appears as though it's not going to occur."

Tenders for the new police station will be called in May.