Am I making a mistake buying a house with a blocked cellar?

i'm thinking about buying a 1920's terraced house partially renovated.I've viewed the house twice now and I must say that the house had a strong odour ?damp although no visible signs although i must admit the skirting boards along the hallway laid wavy along the walls; the estate agent stated that the neighbouring house had a cellar however this house didn't. However whilst on google maps i noticed that the property used to have stairs going down beneath the front of the house (now a block paved driveway) which indicated that the house did in fact have a cellar. I contacted the estate agents to inform them of my discovery which they then contacted the vendor who admitted that there was a cellar but he stated that he filled it with hardcore. I doubt very much that he has filled the cellar hence the smell of ?damp also when I viewed the property the radiators were always on even though the weather was very hot (25 degree) the house is currently empty, no occupants. In hindsight it was an attempt to dry out the property. My question is: should I refrain from buying the property even though i intended on getting full surveys and what would be the approx cost of re- opening the cellar which i would intend to do if i was going to purchase the property however i would want the entry point to the back of the garden instead of the front. Also what damage do you think could have been caused due to blocking off the cellar bearing in mind that the cellar has been blocked since mid 2010 and house remained vacant since then. I thank you all in advance for your advice.