Police have released CCTV footage of a missing mother-of-four on the day she disappeared as the search for her body turns to the woodland near her home.

Samantha Henderson, 25, whose children are one, two, four and six, was last seen in Corfe Castle, Dorset, on Wednesday.

Detectives, who have said they 'strongly believe [Miss Henderson] may have come to some harm', have released CCTV footage and images of the young mother in The Sweet Shop in The Square in Corfe Castle at 11.41am the same day.

A 27-year-old man from the village, believed to be her boyfriend, was arrested on Friday on suspicion of her murder.

Scroll down for video

Detectives searching for 25-year-old Samantha Henderson from Corfe Castle, Dorset, have released CCTV footage of her the day she disappeared

Detectives leading the major investigation have today released CCTV footage and images of Samantha in The Sweet Shop in The Square in Corfe Castle at 11.41am on Wednesday 21 January 2015

Detectives have been granted a further extension of detention until 5pm on Tuesday evening to question the man who is currently assisting police with their inquiries.

She can be seen in the footage moving animatedly around the shop wearing a pink jumper or coat and light blue jeans. Her long blonde hair is tied up in a ponytail.

She appears to buy cigarettes from behind the counter while chatting to the shopkeeper and hesitates at the till as she enters her pin number before leaving the shop.

The last confirmed reported sighting of the mother-of-four was at around 3pm on Wednesday outside Corfe Castle Primary School in East Street.

Police helicopters have scoured the area, while 35 major crime officers and forensics experts combed allotments, outbuildings and the missing mother's home.

Detectives leading the search for the missing mother are appealing for the public's help

A spokesman for Dorset Police said: 'The CCTV shows Samantha in the clothing she was seen wearing outside the primary school later that afternoon - a pink jumper or coat and light blue jeans. She had her long blonde hair up in a ponytail.'

Senior investigating officer Det. Insp. Devoto said: 'We have not found Samantha yet and are gravely concerned about her, fearing that she may have come to some harm.

'We are releasing this CCTV footage taken on Wednesday morning, which is the day she was last seen. I am urging anyone who may have information about what happened to Samantha or who saw her after 3pm on Wednesday to please get in contact with Dorset Police.'

Detectives seized Miss Henderson's blue Peugeot from her home last night and asked the public to help trace the car's movements – especially between 3pm on Wednesday and 10.25am on Thursday.

Dorset Police said she was a 'prolific phone user' but that her mobile had not been found.

Miss Henderson lives in a £325,000 four-bedroom cottage. It is believed her partner lived there for several years, but there is a 'for sale' sign outside and she had arranged to meet a house clearance firm yesterday.

Det Insp. Devoto added: 'I am very keen to hear from anyone who may have travelled along the A351 and in the Corfe Castle area between 3pm on Wednesday January 21 and 5pm on Friday January 23 and captured their journey on CCTV or cameras in their cabs, cars or on their motorbike or bicycle helmets.

She can be seen in the footage moving animatedly around the shop wearing a pink jumper or coat and light blue jeans. Her long blonde hair is tied up in a ponytail

She appears to buy cigarettes from behind the counter while chatting to the shopkeeper and hesitates at the till as she enters her pin number before leaving the shop

Officers have urged anyone who may have information about what happened to Miss Henderson or who saw her after 3pm on Wednesday to please get in contact with Dorset Police

This footage may be very useful to my investigation and I urge you to call me.

'Extensive investigations are ongoing, including forensic experts examining Samantha's home address in Corfe Castle. Searches are also being carried out in the Corfe Castle village area.

'Our search for Samantha is continuing and we are desperate for any information about her whereabouts. Samantha's disappearance is completely out of character as she has never gone missing before leaving her four young children who are aged one, two, four and six.

'We urgently want to hear from anyone who has seen Samantha after 3pm on Wednesday, had contact with her whether by phone or social media or has any information of her whereabouts.

'We are keeping an open mind about what may have happened to Samantha but are fearing the worst. We need the public's help and anyone with information, no matter how seemingly insignificant, should call Dorset Police as soon as possible.'

Miss Henderson, pictured this Christmas. Dorset Police said she was a 'prolific phone user' but that her mobile had not been found

Dorset Police are asking for help in tracing the movement's of Miss Henderson's car, pictured, which is a blue Peugeot 307 estate

'Devoted' mother-of-four Miss Henderson was last seen in Corfe Castle, Dorset, on Wednesday

Miss Henderson is described as white, 5ft 3ins tall, of a very slim build and with long blonde hair.

Over the weekend, Miss Henderson's family issued a statement pleading for her to come home.

They said: 'Sam is a homely, private, loving mother of four children aged six, four, two and one.

'She is hard-working, always presentable and this is completely out of character for her.