A 41-year-old man from Rotterdam has been jailed for 25 years for killing a retired couple after boarding their boat and attacking them with a weapon, before throwing them into the water.

Lammert and Marga Westra disappeared on a Monday afternoon in early March last year after going to show their small motorboat to a prospective new owner. Their children raised the alarm after the couple, aged 68 and 70, did not return home.

Police found their bodies in the water on the Tuesday and confirmed they had been killed.

Sjef R had faced 30 years in jail. He is said to be ‘known to the police’ and has no permanent address.