A legal expert has concluded Nadene Lomu may not be able to stop a documentary being made about her late husband.

Jonah Lomu’s widow has written a cease-and-desist letter to the New Zealand Film Commission over a proposed documentary about the deceased rugby star.

Nadene Lomu said she had trademarked and owned the intellectual property for 'all and anything' related to Jonah.

AJ Park litigation principal Thomas Huthwaite says Nadene Lomu won't be able to prevent an independent story from being told.

"On the other hand, if she's looking to prevent the use of the name Jonah Lomu as a trademark or in any other way that suggest authorisation- then she might have an argument for that."

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