Detectives are offering a £10,000 reward successful the hunt for Constance Marten, her spouse and newborn baby.
Police judge the 35-year-old is sleeping unsmooth with her kid and spouse Mark Gordon, 48, a convicted enactment offender.
The trio were past seen successful Newhaven, East Sussex, 3 weeks agone and are thought to beryllium utilizing camping instrumentality to unrecorded disconnected grid.
Police fearfulness the babe has been "exposed to sub-zero temperatures".
The Metropolitan Police said they had arrived astatine the larboard by taxi conscionable earlier 05:00 GMT connected 8 January, but they believed the household were inactive successful the UK.
They were seen carrying a bluish two-man tent, sleeping bags and pillows they had purchased from Argos the erstwhile evening.
Police added that "the babe was live and with them erstwhile they got the taxi to Newhaven".