Senior officers involved in the search for Madeleine McCann have been seen regularly going out for two-hour lunches. As her parents completed 13 gruelling interviews and meetings with politicians in Berlin on Wednesday, two of the leading officers in the case were seen enjoying a leisurely lunch.

Chief Inspector Olegario Sousa and Goncalo Amaral, the head of the regional Policia Judiciaria, joined two other men at a speciality fish restaurant called Carvi a few minutes’ walk from police headquarters.

A fellow diner said the men laughed and joked as the McCanns appeared on a television news broadcast.

“They asked for the Portuguese TV news to be switched on and sat at the table watching it,” he said. “Madeleine’s parents had given a press conference in Berlin . . . The police were laughing and joking among themselves while it was on. They seemed to be sharing some sort of in-joke. I thought that laughing like that in public was in really poor taste.”

The party shared a bottle of white wine and there was what appeared to be a bottle of whisky on the table during the lunch, which lasted almost two hours. The fellow diner said: “Someone on another table seemed to know them and joked about them having two-hour lunches and knocking back Johnnie Walker Black [Label].”

Mr Sousa, the official spokesman for the investigation, defended the officers when asked if he thought it was acceptable for them to drink wine and whisky in their lunchtime while involved in such a major investigation.

“It is very, very sad but a person’s free time is for lunch,” he said. “The persons are in charge in the day, they are working in the day but they must eat and drink, it is normal. I drink what I want to drink when I can drink.”

Asked whether it was normal for police to drink whisky at lunchtime, he replied: “I don’t have to answer that because the persons during lunchtime do what they want to do. It is free time. They are not working at that time.”

When told that he had been seen drinking whisky and wine with colleagues, he replied: “I still say to you what I do in my free time is only responsible and in my interest. It is my lunchtime. What does it have to do with you what I drink or what I eat? Have you seen anyone drunk? Have you seen any action deterred by that?”

Madeleine’s family reacted with shock at news of the police’s behaviour. Her grandmother, Eileen McCann, 67, said: “I’m not happy about that. My worries are for Kate and Gerry.”

The missing girl’s aunt, Philomena, said: “If it were detectives from Scotland Yard there would be absolute uproar. But we have to let them get on with their work because that’s all we have to rely on.”