A 34-year-old woman covered in bruises has accused police in Frankston of committing a violent attack during a roadside incident.

But Victoria Police refuted her allegations of police brutality, saying the woman injured herself during an arrest.

Elisha Sherwood and her partner Daniel French, both of Frankston South, were pulled over on Young Street in Frankston around 1.30am on Friday.

Ms Sherwood says police bashed her during a 30-minute ordeal in Melbourne's far south-eastern suburb.