A senior health official has said the number of people in eastern Pakistan suspected to have died in the last month from taking bad heart medicine has risen to 70.

Saeed Illahi said on Wednesday that an investigation found that a total of 419 heart patients had become sick from taking the drugs, and that 45 of them remained in critical condition. Many of the patients are in the city of Lahore.

Illahi is the head of the health department in Punjab province, where Lahore is the capital.

The suspected drugs were given free to patients by the state-run Punjab Institute of Cardiology.

Illahi said the government had registered a case against the company accused of manufacturing the faulty medicine.

Javed Akram, another government health official, said patients developed red spots on their skin within days of taking the medicine that is suspected of killing them.

Al Jazeera's Imtiaz Tyab reports.