to have gone underground.

[user_gary]

The Enforcement Directorate is now waiting for Ali’s account details from the Swiss Bank to finally nail him.

Known for his affluence and interest in breeding thoroughbred horses, Ali was questioned after the raid on his premises across Mumbai, Pune, Hyderabdad and Bangalore. However, the taxmen failed to procure documents and necessary warrants to arrest him. Ali now seems to have gone underground.

Please explain the highlighted words.

[Anglika]

The Enforcement Directorate is now waiting for Ali’s account details from the Swiss Bank to finally nail him.

Known for his affluence and interest in breeding thoroughbred horses, Ali was questioned after the raid on his premises across Mumbai, Pune, Hyderabdad and Bangalore. However, the taxmen failed to procure documents and necessary warrants to arrest him. Ali now seems to have gone underground.

Please explain the highlighted words.

in breeding [thoroughbred horses] horses used for horse-racing. To breed = produce offspring (foals, in this case)

Ali now seems to have gone underground. Ali has disappeared/cannot be found