The police made the appeal on broadcaster Mitteldeutsche Runfunk's 'Kripo [criminal police] Live', a television programme presenting unsolved police enquiries, which is shown every Sunday evening.
The calls that the police received mainly centred on a pair of keys found at the scene of the attack.
As well as the keys, the police also presented a black glove and the canister which contained the petrol used in the attack.
Arsonists struck the block of flats, which was being renovated as a refugee home, during the night of April 4th in the small town of Tröglitz in Sachsen-Anhalt.
Tröglitz has witnessed serious contention between the far right National Democratic Party (NPD) and the town authorities.
In March the town mayor stepped down from his position after the NPD demonstrated outside his house over plans to house refugees in the town.