A man posing as a roofer allegedly tricked an elderly woman into writing a cheque for tens of thousands of dollars for repairs she didn't need. 

The 73-year-old told police the middle-aged man visited her Sydney apartment last month, and once inside, told her the unit required 'urgent repairs'. 

Police believe the man was also able to access her personal financial details. 

The woman said the tradie accompanied her to the bank the following day where she was allegedly coerced her into handing over a cheque for the advance payment. 

She later cancelled the cheque and contacted police.

Police have since released CCTV footage of the man, who is seen wearing a black shirt, blue denim jeans and a cap as he walked through a shopping mall. 

He is described as being of Caucasian appearance, about 180cm tall, aged in his 40s or 50s , and with a distinctive, possibly Irish, accent. 

Police believe the man drives a white van and is usually accompanied by a second man, also believed to be Caucasian. 

Inner West Police Area Command Crime Manager, Detective Inspector Benjamin Kennis, has urged older people to remain alert to scams. 

'These [alleged] scammers are targeting older people and claim that urgent home repairs are necessary, demanding large sums of money for work that is not needed,' he said.

'We would always recommend anyone approached like this should take the time and check these people are correctly licensed; these details can be checked with authorities such as NSW Fair Trading, Service NSW.

'It would also be a wise move to get a second, independent quote from known appropriately-licensed tradesmen to be sure your house actually needs the work.

'If you feel intimidated by someone at your home, close the door and contact your family or the police immediately.

'It is also important not to allow these people to accompany you to your bank or other financial institutions to for payment, as you can be vulnerable in this situation as well.'