When the Social Democrat Anders Johansson takes his place as chairman of the municipal board in Sigtuna in 2002, one of his election promises is to build new housing.

In the coming years, the municipality will be Sweden's fastest growing - and it is a construction company that gets most of the projects: Peab housing.

Assignment review can now reveal a close collaboration between Anders Johansson and the CEO of Peab housing, Tomas Andersson.

Documents that Assignment review has received show how the municipal management planned construction projects where it was agreed in advance that Peab would build and the municipality would buy the homes when they were ready.

Sources within Peab believe that the municipality rounded up the law on public procurement, LOU, which is to guarantee that companies can participate and compete on equal terms.

Anders Johansson, who today has changed his last name to Sandén and left politics, says that they did not round LOU.

But Andrea Sundstrand, associate professor of public law at Stockholm University, can take part in the documentation.

- If it is now the case that you have a meeting and already then decide that a company should be allowed to deliver this, then it is clearly a violation of the principle of equal treatment because other companies do not have the same opportunity to come in and be allowed to deliver, or even compete.

“There is only one limit”

Peab housing CEO Tomas Andersson settles most of the business in Sigtuna with Anders Sandén.

At the same time, Assignment Review can tell you that Peab paid for posters and polling booths for the Social Democrats' election campaign in the 2010 election.

Marie Axelsson (S), opposition councilor in Sigtuna and former member of the municipal council, may take part in the information.

In general, what is okay to receive?

- There is only one limit and that is that each party must pay for its own election campaign.

Anders Sandén denies that Peab sponsored him and the party, despite the fact that Assignment review shows him the invoices where it appears that Peab was responsible for the cost.

- I have no reason to believe that we have not done the right thing for us.

"Assuming we did the right thing"

The former municipal council claims that the costs for the polling booths were probably so high that the party disputed them and sent the invoices back to Peab.

But according to the invoices, that is not true.

Nor have the Social Democrats in Sigtuna found anything that confirms Anders Sandén's information.

The current chairman of the party, Björn Stenutz, was a former party auditor and has reviewed the accounts.

His conclusion is that the party did not pay for the polling booths, he says.

- Peab should not buy polling booths for us, that is the basic principle.

According to Assignment review sources, Peab also ordered and paid for the posters.

Nor does the party find anything there that indicates that they were responsible for the costs themselves.

- If they had offered it, I think it is very strange and it is not good.

But I assume that we have done the right thing in the party, says Anders Sandén.

Peab: Can't rule out sponsorship

In emails that Uppdrag granskning has received, it appears that Anders Sandén was involved in the creation of the election posters.

On 25 August 2010, just weeks before the election, an email will be sent to the municipal council with the headline: "Signs 7x10 meters".

"For your information, the original posters (poster on you and message poster) have been sent to Peab", it says in the email.

Assignment review has tried to get an interview with Tomas Andersson, who refers all questions to Peab.

They respond via email:

"We have now gone through all the sponsorship agreements and sponsorship invoices back to 2010 and have not found any sponsorship of political parties, but with that said, it can not be ruled out that it has happened anyway.

It is possible that the local Peaborg organization may have sponsored both polling booths and banners in Sigtuna 2010. ”

In the 2010 election, the Social Democrats in Sigtuna made their best choice with over 42 percent of the vote.